1. Field of the Invention
The present invention relates to a photocathode plate for releasing photoelectrons through photoelectric conversion of incident light, and an electron tube using such a photocathode plate.
2. Related Background Art
In the photocathode plate of this type, a semiconductor light absorbing layer and a semiconductor electron emission layer are deposited in this order on a semiconductor substrate, and an electron releasing portion for outwardly releasing photoelectrons is formed on the semiconductor electron emission layer. Furthermore, an electrode electrically connected to the electron releasing portion is formed on the semiconductor electron emission layer (e.g., reference is made to the specification of Japanese Patent No. 2923462).